Pneumatic separating system.



H. M. PLAISTED.

PNEUMATIC SEPARATING SYSTfM.

APPLICATION FILED FEB. 23.. 19"}.

72,3 1 1 Patented July 9, 1918.

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To all whom it may concern:

Be it known that I, HAROLD M. PLAISTED, a citizen of the United States, residing at Granite City, in the county of Madison and State of Illinois, have invented certain new and useful Improvements in Pneumatic Separating Systems, of which the following is a s ecification.

his invention relates to certain new and useful improvements in pnematic separating systems, being especially applicable to metal and gravel catc ers in feed grinding systems. The peculiarities of my invention will be hereinafter described and claimed.

The object of my invention is to regulate the quantity and velocity of air admitted to the suction side of a fan, in order to vary its action on the feed material and contained foreign matter, such as metal and gravel.

In the accompanying drawing on which like reference letters indicate corresponding parts,

Figure 1 represents a grinder and a pneumatic feed separating system embodying my improvements; and Fig. 2, an enlarged view of a part of such system.

A designates a grinder and casing with bearings for a shaft B, rotated by a pulley C, and having a flywheel fan and easing D, connected by pipe E .to the bottom of the grinder. F is a horizontalv feed pipe connected to the fan through the grinder, and G a rectangular vertical pipe extension with its lower end open. A side opening in said vertical pipe is provided with a lateral hopper H with a slanting bottom h, and a regulating valve 1, preferably automatic by which the feed material is admitted from a chute J connected to a receiving hopper K. The flywheel fan, or other source of suction, causes a strong current of air to enter the open end of the pipe G and carry the feed alone upward and over through pipe F to the grinder, then through pipe E to the fan, and thence it is blown to a collector (not shown). 'Along with the I feed proper taken in by the receiving hopper K there is often found sand, gravel, washers, buckles, nails, screws, nuts, bolts, miscellaneous iron and other foreign matter that will fall out of the bottom end of the pipe G when the air suction is properly regulated. An air inlet, such as a sh sleeve.

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admit air above the lateral feed hopperH,

and thus lessen the suction in the pipe G; for some light feed material this regulation is suflicient to eflect the separation of the feed itself from foreign matter, but for other feed material it is desirable to regulate the air inlet below the lateral hopper. A slide valve 0, operated by a handle 1?, or otherwise, is mounted snugly between the bottom It and a uide Q, so as to form a continuation of tlie slanting bottom of the hopper H. At the lower end is a depending apron R, hinged or otherwise pivoted thereto, and having a coil spring S, or other means that tends to keep the lower edge 7' of said apron in sliding contact, against one side of the pipe G,-in any adjusted position of the slide valve 0. Dashed lines in Fig. 2 indicate such adjustment of the valve and its apron. A thumb-nut T, serves to maintain the slide valve in position. The apron deflects the air current past the lower edge of the valve without forming a pocket or edd below the same, whatever the position 0 the valve. The velocity of,the entering air current is increased under uniform fan power, according as the opening is lessened, since the fan seeks to obtain its full capacity of air; this increased velocity with less quantity of air, facilitates handling other varieties of feed and foreign matter mixed.

Furthermore, this slide apron valve in conjunction with the sleeve valve,one located above the lateral feed inlet, and the other below it,gives a finely graduated control of both the quantity and the velocity of the air current, that allows its adaptation to a wide range of variety and condition of the feed material supplied to the system.

While I have shown my improvements in connection with a flywheel fan and a grinder, I do not limit my invention to the construction and arrangement shown.

I claim:

1. In a pneumatic separating system, ,the combination with a vertically positioned pipe, subject to an upward air suction having a regulatable feed inlet at one side, and a downwardly inclined hopper bottom communicating with said feed inlet, of a slide valve located below and parallel to said bottom, to deliver the gravitating feed and foreign matter off its bottom edge, and

, .acooarorr velocity past said edge, and an apron pivotally supported by the bottom edge of the slide, inclined downward and backward to a sliding engagement with the side wall of said pipe, substantially as described.

2. In a' pneumatic separating system the combination with a vertically positioned pipe subject to an upward air suction, havm a regulatable feed inlet at one side, and a downwardly inclined hopper bottom, communicating with said feed inlet, and an air inlet valve above the feed inlet to lessen the air suction and mix air with the passing feed, of an inclined slide valve mounted below said bottom to form a continuation thereof, a depending backwardly inclined apron pivoted to the bottom edge of the slide valve, with its lower edge in slidable' contact with one side-of said pipe, whereby is provided an air inlet valve above the feed inlet to vary the quantit of air sucked in, and an air out off valve elow the feed inlet to vary the velocity, whatever the quantity of air in said system.

In testimon whereof I have afiixed my signature in t e presence of two Witnesses.

HAROLD M. PLAISTED. 

